This research will be done in Poland to provide materials to support NIH Grant GM22939. The ultimate goal of the parent grant is to characterize the forces directing RNA folding, and to use this knowledge to reliably predict RNA structure from sequence. One goal of the FIRCA grant is to develop a series of oligonucleotides that bind tightly and specifically enough to RNA to allow interrogation of RNA secondary structure by assaying binding of an RNA to an array of all possible 7-mers. It is possible that even shorter oligonucleotides may be sufficient. The results of this array assay will provide constraints for computer algorithms that predict structure from sequence. A second goal of the FIRCA grant is to develop model systems for studying the interactions that determine the stabilities of multibranch loops.